Raspberry crazy ants are on the move

COLLEGE STATION – Matagorda County has been added to a growing list of counties with confirmed Raspberry crazy ant populations, said a Texas AgriLife Extension Service entomologist.

Dr. Bastiaan “Bart” Drees, of College Station, said the new find increases to 18 the number of counties with known areas of spot infestations.

The ants are an exotic invasive pest first found in the Houston area in 2002, according to Drees.

“Their sheer overwhelming numbers are a major distinguishing characteristic,” he said. “They are uniformly sized one-eighth-inch long, reddish-brown ants, often seen in the millions. They form loose foraging trails, but also forage randomly. They crawl quickly and erratically which gives them their name ‘crazy ant.’ They can, but rarely bite and have no stinger.”

Drees said the special expanded use label for the insecticide Termidor, manufactured by BASF, is one of the few effective control treatments available to protect homes and other structures. Before Termidor can be used though, entomologists with AgriLife Extension or Texas AgriLife Research must first confirm that Rasberry crazy ants are in the county.

“It’s important for those with ant infestations to know that the special use label for Termidor is available, but only to pest control operators in the affected counties,” Drees said.

“Harsh winters have reduced populations the past two years,” he said. “But the ants survive and rebound by early summer, forming large colonies that grow larger through the summer months.”

“Since the best controls are only available from professional pest management providers, we discourage homeowners from trying to manage this pest on their own. That’s because the populations become so large that they often cross property lines and re-invade treated areas which then requires multiple control applications.”

Drees said homeowners finding very large numbers of reddish, uniformly sized ants crawling “everywhere” are encouraged to have the ants identified by collecting and sending samples to the Center for Urban and Structural Entomology using the downloadable form available at http://urbanentomology.tamu.edu .

“Identification is an important step because newly infested counties will be added to an expanded-use label for Termidor by the Texas Department of Agriculture, available at http://urbanentomology.tamu.edu/pdf/termidor section18.pdf , which enables pest management providers to provide the more effective treatment,” Drees said.

To stop the ant invasion, Drees advises homeowners to examine articles coming from the Texas counties known to have Raspberry crazy ant infestations as noted on the urban entomology website.

“Items including mulch, potted plants, trash, landscape elements or any other article that has had ground contact should be inspected for ants before it’s placed in the landscape,” Drees said.

“These ants spread primarily by hitching a ride in infested articles from one area to another rather than by mating flights,” he said. “Ground-based spread is estimated to be about 300 feet per year. These ants displace many other ant species including the red imported fire ant. They have no central nests, but instead, nest under almost all structures in the landscape.”

The website http://urbanentomology.tamu.edu/ants/exotic tx.cfm posted that the ants can cause great annoyance to homeowners and businesses. Wildlife such as nesting songbirds can be affected, but so far the extent of their economic impact is unknown.